Capps entered with one out in the eighth to preserve a 3-2 lead, but Schumaker hit his first career pinch-hit homer on an 0-1 pitch. Capps threw a strike to Pujols before hitting him in the left side.
Pujols glared at Capps while trotting to first base, but made no move toward the mound. Home plate umpire Mike Estabrook immediately ejected Capps without warning either dugout.
Pirates manager John Russell came out briefly to argue, but Capps said little before quickly leaving the mound.